[dcraw]

I think it's similar to why people don't just set up an AWS box and cron rsync instead of using Dropbox. Or the same benefit as using Heroku over AWS directly. If you're not deeply familiar with server administration, there are a hundred or so snags in managing synchronization of code and data between systems, getting the remote system set up to run the same code as your local system, and managing all the runs and results.